The present invention relates to marine vessels, and in particular to a coupling for marine vessels. Still more specifically the present invention relates to an apparatus for coupling together a pushing vessel and a pushed vessel so that one of the vessels can act as a rudder for steering the other vessel.
It is already known to push one marine vessel with another, rather than to tow it. The application of so-called "push-towing" was originally confined to protected waters, but has in recent years been extended to rough-water areas also. It is of course possible not only to push a single vessel, such as a barge or lighter, but to push a whole string of such vessels with a single pushing vessel. The pushing vessel has it bow connected with the stern of the pushed vessel, or with the stern of that one of a string of pushed vessels that is closest to the bow of the pushing vessel, by means of a thrust coupling that is usually centrally located on the cooperating bow and stern.
In order to be able to maneuver, that is to be able to use the pushing vessel in its entirety as an active rudder for steering the single or multiple pushed vessels, rope or cable tackle is arranged which extends laterally of the connected vessels and is multiple-reeved so as to be trained about two direction-changing instrumentalities, e.g. rollers or the like. One of these instrumentalities of each tackle is located as far astern on the pushing vessel as possible, and the other is mounted on the stern of the pushed vessel, as far laterally offset from the longitudinal center line of the vessel as possible. One end of each tackle is fixedly mounted and the other end of the tackle is connected to a winch or an analogous device, for example a hydraulic or pneumatic cylinder and piston unit, for the purpose of tensioning or relaxing the respective tackle. By tensioning the tackle on one side and relaxing it on the other side, the pushed vessel and the pushing vessel can be made to perform relative to one another a movement about a vertical axis that is defined by the thrust coupling, so that the pushing vessel acts in its entirety as a rudder for steering the pushed vessel.
However, the constructions known from the prior art do not permit precise individual control of the tackle at the respective sides of the pushing vessel, so that the maneuverability of a coupled pushing and pushed vessel is relatively imprecise. This of course has the disadvantage of not only making it difficult to maneuver the connected vessels, but also of increasing the danger of accidents since the inadequate maneuverability makes it more difficult to avoid collisions and the like.
Moreover, the prior-art constructions require specialized winch constructions, insofar as they use winches, which must be designed for the particular application and are therefore relatively expensive. Standard winches cannot be used.